1. Field of the Invention:
The present invention pertains to resection of bones for receiving prosthetic components of particular use in knee replacement procedures and, more specifically, to methods and apparatus for arthroscopic knee replacement.
2. Discussion of the Prior Art:
Prosthetic replacement of the knee is a procedure of substantial importance to recreate the knee joint with a pain-free functional arc of motion and antero-posterior and varus-valgus stability. The knee is, basically, formed of medial and lateral tibial plateaus, medial and lateral femoral condyles and menisci between the tibial plateaus and the femoral condyles along with the patella which covers the anterior surface of the knee, and prosthetic replacement of the knee as described herein relates to the tibial plateaus, the femoral condyles and the menisci. Various types of prostheses are presently available, as described in detail in Replacement of the Knee, Laskin, Denham and Apley, Springer-Verlag Berlin Heidelberg, 1984, and are commonly grouped as partial or unicompartmental replacements of the medial or lateral portion of the tibio-femoral joint, surface replacements to prevent contact between worn surfaces and jack the joint surfaces apart, linked joints and fixed hinge joints. The type of prothesis employed must be matched to the needs of the patient. By selecting the proper prothesis, antero-posterior and varus-valgus stability can be achieved by prosthetic replacement coupled with bone surfacing or resection. In the past, prosthetic replacement has been a last resort in treatment for knee problems due to the facts that prior art protheses and surgical procedures have not led to reliable, close to natural, results and the open surgery required results in great trauma and substantial recovery time. Much effort has been expended in attempts to improve the accuracy with which articular joint surfaces can be positioned with leg alignment; however, procedures and apparatus available at this time do not provide the required accuracy to restore normal leg alignment and prevent early failure of the prothesis.
Open surgery required for prior art prosthetic replacements typically necessitates a long incision, on the order of ten inches, along the anterior midline of the knee from above the patella to below the tibial tubercle followed by a deep dissection around the medial border of the patella and along the patellar ligament to the tibial tubercle with detachment of the medial third of the quadriceps attachment from the upper border of the patella. The tendinous margin is then pulled downwards and medially while the patella is pulled downwards and laterally. The quadriceps tendon is then split, and the patella is displaced laterally and everted. While the above is a simplified explanation of open knee surgery, it serves to explain the substantial trauma and recovery time associated therewith. Arthroscopic surgery has been used for many surgical procedures on the knee to avoid open surgery with great success; however, the obstacles presented by articular bone surface resecting or shaping to receive an implant coupled with the need for precise positioning and alignment of the prostheses has been insurmountable with arthroscopic procedures prior to the present invention. Not only is there a great need for an arthroscopic prosthetic knee replacement procedure but there is also a great need for improvement in the accuracy of prosthesis placement to restore normal leg alignment.